import java.util.Scanner;

public class Test17 {
    public static void main(String[] args) {
     Scanner sc = new Scanner(System.in);
        int i = sc.nextInt();
        int j = sc.nextInt();
        int result =0;
        for (int x=i; x<=j; x++){
            if(x%8==0){
                continue;
            }else {
                result+=(1.0*x/2)*(x+1);
            }
        }
        System.out.println(result);


    }
}
